Why do back-pressure steam turbines have a protection mechanism against too low exhaust pressure, but not one against too high exhaust pressure?
Thread Content
Why do back-pressure steam turbines have a protection mechanism against too low exhaust pressure, but not one against too high exhaust pressure?
We used to have a interlock mechanism for low exhaust pressure, but it was later removed. There is a safety valve for exhaust – so how can there be no protection against high pressures? The inlet and exhaust pressures affect the axial thrust of the turbine; if the backpressure is too low, the axial displacement increases as well, and vibration levels rise as well, all of which can trigger the interlock mechanism
The exhaust pressure is low, causing the steam in the extraction pipeline network to flow back
A high exhaust pressure protection can be set.
If the exhaust pressure is low, it won’t enter the pipeline network
The backpressure must be higher than the pressure in the steam pipeline network
The high exhaust pressure is protected by a safety valve, so there’s no need to worry. The design of equipment includes self-protection features; only by protecting themselves can they ensure human safety.